Day 10: Starting Seeds Indoors, Part 2

Yesterday’s topic was starting seeds for your vegetable garden indoors in trays or containers of potting mix, which works great for smaller seeds that you sprinkle on the surface of your planting medium. Today I’ll talk about ways to start larger seeds.

Tomato and pepper seedlings thrive in their peat pellets.

When you go to the seed-starting section of your local garden center, you’ll find a variety of products available. Cell packs of either plastic or degradable fibers have long been available—you just fill them with a seed starting mix and start planting. Some people like to start seeds in the pot they’ll stay in until they’re planted outdoors—there are lots of options for them as well, including homemade. I know some gardeners who make their own starter pots by rolling layers of wet newspaper around bottles and letting them dry.

What you’ll most often find in the stores are seed-starting setups using peat pellets as the base. They’re compressed discs of peat encased in thread-like netting, and are designed to be used with plastic trays molded with depressions that hold them in place, and which have clear plastic lids that keep in humidity. Once the seeds are started, you can either transplant the pellet into a larger container or directly into the ground.

Some people don’t like the pellets, for a variety of reasons; they say they dry out too quickly, or they don’t like the netting and question its biodegradability. Others have a problem with the peat itself, because it’s a non-renewable resource.

After using them over the last few years, they’ve become my preferred way to start most of my peppers, tomatoes and other seeds, and I’ve managed to overcome the first two objections to them. As for the last issue, since my vehicle is powered by a non-renewable resource that enables me to give away many hundreds of pounds of vegetables grown from seeds started in the pellets, it’s a tradeoff I’m prepared to make.

Besides, I’ve found that peat pellets work great for my purposes. Several manufacturers produce them along with the fitted trays, but I prefer the ones from Jiffy. Their pellets are 1-1/2 inch in diameter, and large enough to start two seeds in one. (I do not like the systems that are supposedly “self-watering”.)

I use the trays that hold 25 pellets, and when I open a new one I first prepare it by using a silver permanent marker to label the sides of the black plastic with a numbered grid for each of the growing cells; A1, A2, A3, B1, B2, etc. This enables me to keep track of the variety of seed by noting the cell in which it’s started.

Once I’ve numbered the tray and the pellets are all in their holders, I place the tray in the sink and slowly start running warm water over it and around the sides. The goal is to evenly cover every area of the tray. Soon the pellets begin to expand and rise as they take up water in the tray. I keep trickling in more water until the pellets can’t absorb any more, and I dump out any excess. If you don’t fully soak the pellets at this stage, you’ll have trouble keeping them moist later.

The next step is planting. I sit down at a table with my seed packs and with a tweezer peel back the netting from the top of each expanded pellet. The pellets are now quite soft and have expanded a couple of inches above the surface of the tray. I shake out a few seeds in my hand and then with the tweezer carefully push one slightly beneath the surface on one side of the pellet, and do the same with another seed on the opposite side. Then I record in my notebook which variety I just planted, and move on to the next. When the entire tray is planted I place the lid on it and under the lights it goes. Once most or all of the seeds in the tray germinate I remove the lid and check the moisture level in the pellets, watering them a little if needed.

—Tom McKusick

Follow Notes from Northern Gardener throughout January as we offer our series on 31 Days to a Great Northern Vegetable Garden. Tomorrow: Transplanting and hardening off seedlings.